PROBLEM | CAUSE | CORRECTION | 
Knocking Noise.  | Possible defect in safety  | Operate safety valve manually  | 
  | valve.  | by pulling on ring. If valve still  | 
  | 
  | leaks, it should be replaced.  | 
  | Defective check valve.  | Remove and clean, or replace.  | 
  | Loose pulley.  | Tighten pulley set screw,  | 
  | 
  | see Parts manual for torque  | 
  | 
  | specifications.  | 
  | Loose flywheel.  | Tighten flywheel screw, see  | 
  | 
  | Parts manual for torque  | 
  | 
  | specifications.  | 
  | Compressor mounting  | Tighten mounting screws,see  | 
  | screws loose.  | Parts manual for torque  | 
  | 
  | specifications.  | 
  | Loose belt.  | Loosen wingnut and then  | 
  | tighten wingnut until it contacts  | |
  | 
  | |
  | 
  | the washer, plus one turn.  | 
  | Carbon   | Have checked by a Trained  | 
  | 
  | Service Technician.  | 
  | Belt to tight.  | Loosen wingnut and then  | 
  | 
  | tighten wingnut until it contacts  | 
  | 
  | the washer, plus one turn.  | 
  | 
  | 
  | 
Excessive belt  | Loose belt.  | Loosen wingnut and then  | 
wear.  | 
  | tighten wingnut until it contacts  | 
  | 
  | the washer, plus one turn.  | 
  | Tight belt.  | Loosen wingnut and then  | 
  | 
  | tighten wingnut until it contacts  | 
  | 
  | the washer, plus one turn.  | 
  | Loose pulley.  | Have checked by a Trained  | 
  | 
  | Service Technician.  | 
  | Pulley misalignment.  | See Motor Pulley/Flywheel  | 
  | 
  | Alignment paragraph in the  | 
  | 
  | Maintenance section.  | 
  | 
  | 
  | 
Squealing  | Compressor pump has no  | See   | 
sound.  | oil.  | the Maintenance section.  | 
  | Loose belt.  | Loosen wingnut and then  | 
  | 
  | tighten wingnut until it contacts  | 
  | 
  | the washer, plus one turn.  | 
  | 
  | 
  | 
27- ENG  | A10260  |